1. Field of Invention
The present invention relates to an apparatus for a ventilation device, such as that used for exhausting heat generated inside the case of electronics devices or equipment to the exterior, and more particularly to a serial ventilation device in which two ventilators are placed longitudinally and operate at the same time.
2. Description of the Related Art
In electronic devices in which many electronic components are housed in a relatively small case, such as office equipment like personal computers and copiers, heat generated by these electronic components collects inside the case and there is concern that the electronic components will experience heat failure.
Accordingly, vent holes have been created in the walls or roof of the cases for these electronic devices and ventilators attached to these vent holes exhaust the heat inside the case to the outside. As methods to force heat exhaust using ventilators there is the normal method, using one ventilator, and the serial operation and parallel operation methods, using two ventilators with good external shape and characteristics in combination at the same time.
In the serial operation method, two ventilators are placed longitudinally facing the same direction such that their rotation shafts are positioned in a straight line and they operate in the same direction at the same time. This method is designed mainly to increase static pressure P. In the parallel operation method, two ventilators are mounted laterally facing the same direction such that their rotation shafts are positioned in parallel and they operate in the same direction at the same time. This method is designed mainly to increase airflow Q.
Accordingly, engineers select the serial operation method or the parallel operation method depending on physical conditions, such as the available mounting space for two ventilators, and/or required specifications such as which of increasing static pressure P or airflow Q has priority. However, in recent years, the miniaturization of electronic devices has been remarkable and the consequent need for improvement in the heat exhaust characteristics required for ventilation devices is notable. For instance, in ventilation devices using the serial operation method (i.e., serial ventilation devices) the effect of even a small increase in airflow Q on the efficiency of exhausting heat generated inside an electronics device's case is large. Accordingly, even for serial ventilation devices recently there have been demands for further increases in airflow Q without increasing the size.